In the metalworking and fabrication fields, the need to create threads in a hole to receive a screw or bolt has existed for quite some time. Many existing devices available for driving a thread tap into a hole are unnecessarily large and cumbersome, especially when one is attempting to tap a hole in an area of limited space. Some devices for driving a tap, such as T-handle wrenches with a collet-type engagement are as long as the tap itself. That arrangement wastes valuable space, making it unusable in tight confines.
Further, three-jaw chucks such as those commonly found on hand drills or drill presses, do an inadequate job of engaging the square profile of a tap. The three-jaws cannot securely engage the four flats of a thread tap. Additionally, six-point sockets or box wrenches are not suited for engaging the square profile of a tap, as a square profile does not securely fit inside a hexagonal profile.
U.S. Pat. No. 5,213,347 to Rulon et al., discloses a tap adapter for use with a ratchet. The tap adapter looks similar to a standard socket, and engages a ratchet just like a socket does. However, Rulon et al. does not solve the problem of how to engage a thread tap into a three-jaw chuck. The outer profile of his tap adapter is cylindrical and would not be able to be held in a chuck if needed. Additionally, in situations where space immediately above the tap is very tight, Rulon's tap adapter requires enough vertical space for a ratchet.
U.S. Pat. No. 5,037,251 to Roth discloses a thread tap having not only the traditional square end profile, but also a shank having a hexagonal profile. However, tap users would need to replace their entire set of taps at a substantially high cost in order to enjoy the benefits of Roth's invention. Additionally, thread taps having a hexagonal shank profile are more complicated and therefore more expensive to manufacture than standard taps. Taps are very hard and brittle, and often break during use. Having to replace higher-cost taps is not desirable for consumers.